Well, apart from the YouTube presentation shown there are actually many
instances where it is necessary to remove all data from a disk i.e to
destroy it completely for say, security reasons. Well you could of
course shred the disk with a purpose-designed document shredder - but
here I am supposing you want to keep the disk. Notwithstandind that in
the presention the "silvering" is shown being "burnt off" or
"evaporated" from the disk witha pole transformer I seem no reason why
this could not be done with a commercially-designed "eraser" say, using
a flyback transformer and SMPS -much smaller and lighter and more
practical.